吡喹酮治疗血吸虫感染小鼠后IFN-γ和IL-4及T细胞的变化

Changes of IFN-γ, IL-4 and T Cells in Schistosoma japonicuminfected Mice after Praziquantel Treatment

目的观察血吸虫感染小鼠经吡喹酮治疗后血清中细胞因子IFN-γ和IL-4的水平，及脾细胞中特异性T细胞数量的变化。方法将90只6～8周龄BALB／c小鼠随机分成3组，分别为感染组、治疗组和对照组，每组30只。感染组和治疗组小鼠经腹部感染血吸虫尾蚴（约25条／鼠）。治疗组小鼠于感染后6周经口给予吡喹酮治疗，300mg／（kg·d）×3d。分别在治疗后4、6、8和12周，对各组小鼠进行称重，采血并分离血清，ELISA检测血清细胞因子IFN-γ和IL-4水平。无菌取小鼠脾脏，制备脾细胞悬液，经日本血吸虫可溶性虫卵抗原（SEA）刺激后，用酶联免疫斑点法（ELISPOT）分别检测分泌IFN-γ和IL-4的特异性T淋巴细胞的增殖水平。结果治疗组小鼠体重在治疗后4～12周均显著大于感染组（P〈0．05），与对照组间差异无统计学意义（P〉0．05）。ELISA结果表明，治疗后4周，治疗组血清中IFN-γ和IL-4水平与感染组间差异无统计学意义（P〉0．05），而治疗后6、8和12周，治疗组的IFN-γ（0．038＋0．013、0．028±0．001和0．027±0．007）和IL-4（0．051±0．020、0．045＋0．019和0．043±0．016）水平均显著低于感染组（IFN．1：0．057±0．004、0．060±0．023和0．052±0．017，IL-4：0．150±0．014、0．148±0．014和0．123±0．017）（P〈0．05），而治疗组和感染组的IFN-γ和IL-4水平均显著高于对照组（P〈0．05）。ELISPOT结果显示，在治疗后4周和6周，治疗组脾细胞中IFN-γ特异性淋巴细胞数量与感染组间差异无统计学意义（P〉0．05），而治疗后8周和12周治疗组细胞数量（39．9±22．8和38．5±6．2）显著低于感染组（141．9±39．3和（06．8±28．6）（P〈0．05）；治疗组脾细胞中IL-4特异性淋巴细胞数量在治疗后4周显著高于感染组（P〈0．05），而后开始减少，治疗后8周和12周（111．3±14．3和113．0±44．2）显著低于感染组（220．3±107．1和208．1±17．2）（P〈0．05）；治疗组和感染组脾细胞中IFN-γ和IL-4特异性淋巴细胞数量均显著高于对照组（P〈0．05）。结论吡喹酮治疗血吸虫感染小鼠后血清中细胞因子IFN-γ和IL-4水平降低，脾细胞中IFN-γ和IL-4特异性淋巴细胞数量减少。

Objective To investigate the serum levels of IFN-γand IL-4, and the dynamic changes of IFN-γ specific and IL-4-specific lymphocytes in mice with Schistosoma japonicum infection after treatment by praziquantel. Methods Ninety BALB/c mice were randomly divided into three groups （n=30） named as infection group, treatment group and control group. The mice in treatment group and infection group were infected with （25＋2） S. japonicum cer- cariae through the abdominal skin. At 6 weeks post-infection, the mice in treatment group were administered orally with praziquantel [300 mg/（kg.d）] for 3 d. At 4, 6, 8 and 12 weeks post-treatment, the mice were weighed, and serum sam- ples were collected. Serum levels of IFN-γ and IL-4 were measured by ELISA. At the same time, the spleens were aseptically removed to prepare cell suspension, and the counts of IFN-γ and IL-4 specific lymphocytes were examined by ELISPOT after stimulation of Schistosoma japonicum soluble egg antigen （SEA）. Results From 4 to 12 weeks after praziquantel treatment, the body weight of mice in treatment group were significantly heavier than that of infection group （P〈0.05）, but no significant difference was found between treatment group and control group （P〈0.05）. At 4 weeks post- treatment, there was no significant difference in serum levels of IFN-γand IL-4 between treatment group and infectiongroup （P〉O.05）. At 6, 8, and 12 weeks after treatment, the serum levels of IFN-γ （0.038~0.013, 0.028~0.001, and 0.027~0.007） and IL-4（0.051~0.020, 0.045~0.019, and 0.043~0.016） in treatment group were significantly lower than that of infection group（IFN-~/： 0.057~0.004, 0.060~0.023, and 0.052~0.017; IL-4： 0.150~0.014, 0.148~0.014, and 0.123~0.017） （P〈0.05）. Serum IFN-γ and IL-4 levels in treatment group and infection group were significantly higher than that of control group （P〈0.05）. ELISPOT results showed that at 4, 6 weeks post-treatment, there was no significant difference in the number of IFN-γ-speeifie lymphoeytes between treatment group and infeetion group （P〉0.05）. While at 8 and 12 weeks after treatment, the IFN-γ-speeifie lymphoeytes in treatment group （39.9~22.8 and 38.5~6.2） were significantly less than that of infection group （141.9~39.3 and 106.8~28.6）（P〈0.05）. At 4-week post-treatment, the IL-4-speeifie lympho- eytes in treatment group were mueh more than that of infection group （175.6~62.3）（P〈0.05）, and then began to decline. At 8 and 12 weeks after treatment, the IIM-speeifie lymphoeytes （111.3~14.3 and 113.01.44.2） in treatment group were sig- nificantly less than that of infection group （220.3~107.1 and 208.1~17.2）（P〈0.05）. The IFN-γ-speeifie and IL-4-speeifie lymphoeytes in treatment group and infection group were significantly more than that of eontrol group（P〈O.05）. Conelu- slon After praziquantel treatment, the serum levels of IFN-γ and IL-4 in mice with S.japonicum infection deerease, and the number of IFN-γ and IL-4 specific lymphoeytes reduces.